Author Topic: So where is it safe to write to RAM in a DOS program?  (Read 1016 times)

Offline ben321

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So where is it safe to write to RAM in a DOS program?
« on: February 15, 2023, 05:48:49 AM »
What regions of RAM are safe to write to in DOS program? I know some are memory mapped hardware like VRAM being located at 0xA0000 for VGA. I know other parts are DOS and those shouldn't be overwritten if you want to avoid overwriting DOS code (especially the DOS interrupt code). And yet other parts map to ROM. So I need to know what regions of memory are actually safe to use as a working space in a program. Note I'm talking about a DOS COM program, not an EXE, so DOS isn't doing much memory management for it (meaning I need to know myself what parts of memory are safe to use as a working space for my program).